• 한국환경보건학회지
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• 제18권1호
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• pp.39-46
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• 1992

It has known that the intermediates formed in acid reactions occuring during anaerobic reactions for instance, acetic acid, propionic acid and butyric acid have significant effects or the formations of biogases(e. g. mainly CH$_{4}$ and CO$_{2}$). A study on the effects of these intermediates for the formations of biogases, however, is still on initial stage due to the type and structural problems of reactor. The primary objective of this reserch program is to provide a funadmantal mechanism of involved reactions using a modified downflow multistage pecked bed bioreactor. As a first stage of this reaserch program, the following theoretical principles was applied 1. Principle of electroneutrality where the molar concentrations of cation and anion in solution are the same. 2. Relationship between the concentration of bicarbonate anion and pH as follows [HCO$_{3}^{-}$]= $K_{H}P_{T}Y_{CO_{2}}10^{pH-K_{1}}$ Based upon the above two principles, a series of experimental works was conducted to elucidated the relationship between the concentration of CO$_{2}$ and the pH related to the concentrations of cations and anions.

• 한국환경보건학회지
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• 제19권3호
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• pp.17-21
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• 1993

Characteristics of a downflow anaerobic packed bed reactor with raschig ring ceramics as a packing were measured and discussed for the basic evaluation of the process. A synthesized glucose substrate wastewater were used as a feed and process characteristics such as pH, biogas production, composition of produced gas, COD removal and VSS were measured with the hydraulic retention time (HRT) changing from 0.25 to 2 days. As a result, this type of reactor was applicable in continuous operation within the given HRT range and the transient period approaching the steady state was about 20 days. The content of methane in produced gas increase with HRT was always high above 50% enough to use as energy source. The COD removal efficiency increased gradually as HRT increased. The axial profile of VSS concentration in the reactor usually showed the maximum at the lower region and the minimum at the middle. The VSS concentration at the upper region and the exit appeared similarly. However, at 0.25 day of HRT, the VSS concentration of effluent became higher than that of the upper region. Therefore the optimum HRT of this reactor occurred about 0.5 day, at which the production of methane began to be just stabilized and loss of VSS and COD removal were resonable.

• 한국물환경학회지
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• 제18권4호
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• pp.379-386
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• 2002

In this study, estimation model for iron compound originated from upflow, anaerobic fixed bed reactor, which treats sewage domestic wastewater, was developed. The estimation model was formulated by a mathematical expression which was based on the mass balance. Below the HRT of 60 minute, sulfide concentration combining with iron $FeS_2$ is the highest because the maximum sulfate consumption rate $V_{maxS}$ and half-saturation constant of sulfate $K_{mS}$ exert an important effect on the estimation model as temperature was increased. But increment of $FeS_2$ concentration is weakened above the HRT of 60 minutes and represent the lowest value at the HRT of 108 minutes. It implies that liquid phase distribution ratio of sulfide ${\alpha}r$ becomes lower as temperature was increased. While phosphorus concentration combining with iron $Fe_3(PO_4)_3$ is increased as HRT and temperature are increased, which is affected by phosphorus removal rate constant $k_p$. As the result of estimating the iron concentrations of corrosion by the model, the concentration of iron corrosion is higher than any other at the HRT of 108 minute and $20^{\circ}C$. The predicted values were compared with measured ones at different HRT(13.5, 27, 54, 108 min) and temperature(20, 25, $30^{\circ}C$). The experimental data could be fitted with the simulated curves. Therefore, the mathematical expression could be applicable to design full-scale wastewater treatment plants.

• 유기물자원화
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• 제23권4호
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• pp.11-20
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• 2015

원지반에서의 저품위 석탄층의 생물학적 메탄 생산을 위한 기초연구를 수행하였다. 인도네시아산 갈탄을 시료로 이용하였으며, 조건을 달리하여 BMP(Biochemical Methane Potential) 실험을 수행하였다. 갈탄에 영양물질과 혐기성 슬러지만 제공한 경우, 온도(23, $30^{\circ}C$)나 석탄의 입자크기는 메탄가스 생산에 영향을 주지 않았다. 이는 가용한 용해성 유기물질이 낮기 때문이다. 외부탄소원으로 볏짚을 갈탄에 첨가한 후 BMP 실험을 수행하였으며, 60일간의 BMP 실험 후 볏짚 첨가에 의한 메탄가스 발생량은 94.4~110.4 mL/g VS이었다. BMP 실험 후 갈탄의 발열량은 볏짚 첨가량이 증가할수록 감소하는 경향을 보였다. 이는 볏짚의 혐기성 분해와 함께 갈탄의 분해가 이루어졌음을 의미한다. 따라서 원지반에서의 저품위 석탄층의 생물학적 메탄 생산의 초기 운전 시에 볏짚을 탄소원으로 사용할 수 있다.

• 한국환경농학회지
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• 제18권1호
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• pp.54-60
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• 1999

축산폐수의 효율적 처리와 최적 메탄발생을 위하여 AF 그리고 이단의 ASBF-PR과 ASBF-SP 실험실적 생물반응기를 구성하고 $35^{\circ}C$ 항온조에서 수리학적체류시간 $1{\sim}2$일 그리고 유기물부하 $1.1{\sim}63kg-COD/m^3{\cdot}d$까지 연속 운전하여 처리효율을 비교, 분석하였다. 하수종말처리장의 혐기성 소화조 잉여 슬러지에 의한 혐기성 생물반응기의 식종은 효과적이었으며, 적응 기간은 약 40일 정도가 소요되었다. 생물반응기는 COD 제거율 $66.4{\sim}84.9$% 그리고 바이오 가스 발생량은 제거된 COD 기준 $0.333{\sim}0.796m^3/kg-COD{\cdot}d$. 으로 축산폐수의 처리에 효율적이었으며 유입 COD의 증가와 수리학적체류시간의 감소에 의한 유기물부하 증가의 경우 COD 제거율은 감소하고 바이오가스 발생량은 증가하였다. 높은 유기물부하에서 AF와 ASBF-PR의 처리효율은 비슷하였으며 ASBF-SP보다 우수하였다. 생물반응기에 충진된 미디어의 공극율과 공극의 크기가 비표면적에 비교하여 유기물질 제거능력 향상에 영향을 미치는 것으로 나타났다. 유입수 TKN 농도가 $1,540{\sim}1,870mg/L$ 범위에서 메탄발효 미생물의 활동은 저해영향을 받아 생물반응기의 처리효율과 바이오가스 발생량은 각각 50% 이하로 감소되는 것으로 나타났으므로 혐기성 소화가 축산폐수의 처리에 주 공정으로 응용된다면 전처리에 의한 TKN의 제거는 필수적이다.

• Environmental Engineering Research
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• 제25권1호
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• pp.80-87
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• 2020

Landfill waste decomposition generates a dark effluent named, leachate which is characterized by high organic matter content. To minimize these polluting effects, it becomes necessary to develop an effective landfill leachate treatment process. The objective of this study was to evaluate the performance of an innovative approach based on air stripping, anaerobic digestion (AD) and aerobic activated sludge treatment. A reduction of 80% of ammonia and an increase of carbon to nitrogen ratio to 25 were obtained, which is a suitable ratio for AD. This latter AD was performed in fixed bed reactor with progressive loading rate that reached 2 and 3.2 g COD/L/d for the raw and diluted leachate (1:2), respectively. The anaerobic treatment led to significant removal of chemical oxygen demand (COD) and biogas production, especially for the diluted leachate. The COD removal was of 78% for the raw leachate and a biogas production of 4 L/d with 70% methane content. The use of the diluted leachate led to 81% of COD removal and 7 L/d biogas with 75% methane content. It allowed a removal of 77% COD and more than 97% of the organic compounds present in the initial leachate sample.

• 한국산학기술학회논문지
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• 제19권2호
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• pp.90-96
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• 2018

기성 유동상 반응기(AFBR)의 수리학적 특성을 고찰하기 위해 "무담체 모드"와 "담체 충진 모드"의 두 가지 모드에서 추적자 실험을 수행하였다. 각 모드에서 동일한 실험조건으로 실험을 수행하여 수리학적 수치들이 유도되었고 실제 반응기의 수리학적 특성파악에 필요한 데이터를 얻어 해석하였다. 두 가지모드에서의 수리학적 해석을 위해 담체는 비 반응성이고 분산계수가 상수라는 가정으로 비 반응성 추적자의 일차원-비 정상상태 농도분포의 분산모델을 사용하였다. 실험결과 담체는 반응기 내부에서의 혼합효과를 크게 증가시켰다. 담체를 충진하지 않은 경우 충진한 경우에 비해 분산계수는 최소 1자리 수 이상 작게 나타났다. 담체가 없는 경우 실험영역(Pe⦤0.83cm/s)에서 이류흐름이 지배적 흐름이었고 반응기의 흐름형태는 마개흐름형 반응기(PFR)에 근접하였다. 이 때 분산계수는 0.83cm/s까지 겉보기유속에 비례적으로 증가하였다. 그러나 담체가 충진된 경우, 흐름형태는 마개흐름형 반응기 (PFR)과 완전혼합형 반응기(CMFR)사이에 있음을 나타내었으며 분산계수는 겉보기유속이 0.41cm/s에서 거의 최대치에 도달한 후 0.82cm/s까지 유사한 수치를 나타내었다. 본 실험조건에서 분산계수는 액체 레이놀즈수(Re) 또는 입자 레이놀즈수(Rep)에 비례하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제9권3호
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• pp.49-55
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• 2004

염화에틸렌 화합물에 오염된 토양으로부터 고농도 (150mg/L)의 PCE를 cis-DCE까지 탈염소화하는 혼합미생물 농화 배양계 LYF-1을 구축하였다. LYF-1은 효모추출물, 펩톤, 포름산, 아세트산, 락트산, 피루브산, 시트르산, 석신산, 글루코오스, 수크로오스, 에탄올 등을 전자공여체로 이용하여 PCE를 탈염소화할 수 있었다. 한편, PCE를 대신할 수 있는 전자 수용체에 의한 PCE 탈염소화에 미치는 영향을 살펴본 결과, NO$_3$$^{-}$와 NO$_2$$^{-}$는 PCE의 탈염소화반응을 완전히 저해하였으나, S$_2$O$_3$$^{-2}$ , SO$_3$$^{-2}$ 및 SO$_4$$^{-2}$ 는 PCE의 탈염소화반응에 그다지 큰 영향을 미치지 않았다. LYF-1 혼합미생물을 혐기성 고정생물막 반응기내의 세라믹 메디아에 부착하고, PCE의 유입부하율 변화에 따른 처리 효율을 조사한 결과, PCE의 부하율 0.13-0.78 $\mu$moles/L/hr의 범위 내에서 99% 이상의 PCE 탈염소화 효율을 보였으며, PCE 탈염소화 반응의 최종산물은 cis-DCE이었다.

• 산업기술연구
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• 제26권B호
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• pp.3-10
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• 2006

In this study, the of MBBR(moving bed biofilm reactor) process for Phosphorus Removal efficiency depending on seasons and the factors affecting phosphorus removal efficiency in the process is evaluated. As a result of experiment, T-P removal efficiency has its highest value in winter, (80.8%). and T-P removal efficiency has its lowest value in autumn, (49%). Optimum SRT for Phosphorus Removal revealed is about 8.8 days and process performs more efficiently as the temperature decreases. It is accepted that nitrate to anaerobic zone is affecting the Phosphorus removal process. With increasing the organic loading rate, Phosphorus removal efficiency also increases. Also, an experiment has been conducted to find out the highest efficiency according to Media existence and it has revealed that Media addition provides better phosphate removal.

• 수도
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• 통권50호
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• pp.20-25
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• 1989

Water quality of river is greatly influenced by sediments of planktons, suspended solids and organic matters being transported by efflenced. The water quality is also affected by their release at the place of sediments with slow flow of water. This paper deals with the Characteristics of Oxygen consumption of sediments in small river which is greatly vary with time. Some typical samples of sediment were taken from both aerobic and anaerobic condition reserved for several months. and, the samples of sediment were checked on the relative ratio of oxygen consumption by nitrification.